Carburetor



Jan. 18, 1927E 1,615,111

J. S. CUFF CARBURETOR Filed June 29, 1922 WIM/8858 55j MM Arm/Mfrs Patented Jan. 18, 1927.

' UNITED STATES NT OFFICE.

JAMES S. CUFF, OF NEW LONDON, CONNECTICUT.

\ CARBURETOR.

Application filed .Tune 29, 1922. Serial No. 571,615.

The present invention relatesto new and useful improvements in charge-forming devices for internal combustion motors and the like. f

It is one of the primary objects of the invention to provide a carburetor in which the proportion of the elements of the charge, that is, the proportion of liquid fuel and air, may be varied at various speeds of operation of the motor to which the carburetor 1s attached.

Itis a further object of the invention to provide means for controlling the supply of air to the carburetor, and, at the same time, proportionately varying the volume of fuel Y admitted to the carburetor.

It is a further object of the invention to operate the fuel varying mechanism automatically upon operation of the means for varying the air admitted to the carburetor.

It is a Vfurther object of the invention to so construct the carburetor that two types of adjustment may be made, i. e., a greater amount of fuel may be permitted to enter the carburetor upon certain air adjustments or a lesser amount of fuel may be admitted to the carburetor on the same air adjustment.

Vith the above and other objects in view, reference is had to the yaccompanying drawings, in which- Figure 1 is a vert-ical sectional View of a carburetor constructed in accordance with the present invention;

Fig. 2 is a sectional view taken on the line 2 2 of Fig. 1, said ligure being partly broken away;

Fig. 3 is a detail sectional view taken on the line 3 3 of Figure l;

Fig. 4 is a detail sectional view taken on the line 4-4 of Fig. 2.

Figure 5 is a fragmentary view in elevation of the end of the carburetor which controls the flow of air and fuel.

Referring more particularly to the drawings, the reference character 11 designates the carburetor body and said carburetor chamber is provided with a plurality of circularly disposed air inlet openings 12. The carburetor chamber 11 is provided with an 0 open end 13, and received in said open end chamber 11. Projecting from the carburetor chamber 11 in alinement with the member 18, is a boss 19, and said boss 19 receives a plug fitting 20, in which is mounted a strainer 21. Secured to the plug iitting 20, by means of a nut 22, is a housing 23, and said housing 23 is connected to a fuel line 24. The plug fitting is provided with a longitudinal passage (not shown), and establishing communication between the longitudinal l r passage in the plug tting 26 and the chamber 23 is an opening 25. The member 18 is provided with a passage 26 which communicates with a passage 27 in the nozzle 16.

Projecting from the closed end of the carburetor chamber 11 is a threaded eXtension 28 and having engagement with said threaded extension 28 is a nut 29, the purpose of which will be hereinafter referred to.

Surrounding the carburetor chamber 11 is a sleeve and said sleeve 30 is provided with a plurality of air inlet openings 31. This sleeve 30 has a flange 32 and the sleeve is held in position upon the carburetor chamber 11 by means of the nut 29 heretofore mentioned. This nut 29 is provided with a set screw 33, by means of which it is maintained against movement on the screw-threaded extension 28 after it has once been adjusted thereon. The sleeve 30 is provided with a suitable connection 34, by means of which is attached to a throttle-operating mechanism and by means of this throttleoperating mechanism the sleeve 30 is rotated about the carburetor chamber 11 to bring the openings 31 in the sleeve 30 into register with the openings 12 in the carburetor chamber l1 in order that vair may be admitted thereto.

1 Surrounding the sleeve 30 is a second in adjusted position by means of a set screw 38. Surrounding the sleeve 36 is a housing 39, and rojecting from the housing 39 is a pipe 40 for conducting air into said housing.

Screw-threaded upon the threaded extension 28 heretofore mentioned. is a second nut 43, and said nut 43 is provided With a set screw 44, by means of Which it is maintained in adjusted position. This nut '-lj is provided with an external screw thread 45, and engaging said external screw thread 45 is a. cap or dome-shaped member 46. f

Carried by the sleeve 30, is a pin 47, and said pin is adapted to engage between spaced ribs 48 formed on the denic-shaped member 46 in such a manner that as the sleeve 30 is rotated about the carburetor chamber 11, the dome-shaped member 46 will likewise berotated about the nut 43. Only one of said ribs isA shown on Figure l, the other rib being located upon the other section of the member 46.

The passage 27 of the nozzle 16 is enlarged as indicated by the reference character 4) and mounted in said enlarged portion is a stem 50, the forward end of which is tapered as indicated by the reference character 51 to form a needle valve for controlling the. flow of fluid through the passage 27. This stem member is provided with a collar 52 and mounted on said stem and having one end engagimr the collar 52, is a eoilspring 53. The reference character 54 designates a sleeve against which the other end of the coil spring 53 abut-s, and said sleeve 54 is carricd by the stem 50. The outer end of this stem 5t) is screw-threaded, as indicated by the reference character 55, and engaged With said threaded outer end is a thumb nut 56. This threaded outer end also carries a. nut 57, which is retained in adjusted position thereon by means of a set screw 58, and said nut 57 is adapted to engage the outer face of the dome-shaped member 46, it being understood that the stem projects throughy an opening in the closed end of said dome-shaped member 46.

The reference character 59 designates a bracket or the like projecting from the dome-shaped member, and pivotally mounted in said bracket 59, as at 60, is a bell crank lever 61, and adapted to rock it about its pivotal point 60, is a pull Wire 62 or the like, which is connected toa suitable operating member at any desired location. The opposite end of the bell crank lever 61 is forked as at 63, and is adapted to engage the thumb nut 56 heretofore mentioned in such a manner that as the bell crank lever is rocked about its pivotal point the needle valve 51 will be moved toward and away from its seat to open and close the passage 27 through the nozzle 16 for the purpose of priming the motor.

lhc reference character 64 designates a stop for the sleeve 30, and said stop is pivotally secured by means of a cap screw 65 or the like, to a projection 71'on the carburetor body. The end 66 of this stop is adapted to operate in a cut-out portion 67 in the end of the sleeve 30, and to maintain the stop 64 normally in engagement with this cut-out portion a coil spring 68 is interposed between the opposite end of the stop and the carburetor chamber 11.

.Connected to the stop 64 is a pull Wire 69, and said pull Wire (Si) is adapted to rock the end 66 of the stop out of the notched portion 67 of the sleeve 30 on to that portion of the sleeve designated by the reference character 70. As the sleeve is rotated with the end 66 of the stop out of engagement with the notched portion, the end 66 of the stop will engage the screw 38 and` prevent further movement of the sleeve relative to 4the carburetor body 11. The stop 64 is pivotally mounted on a projection 71 or the like, and extending through this projection 71 is a passageway 72. Having threaded engagement with this passageway 72, is a screwthreaded stem 73, the outer end of which is provided With a knuried head 74. Engaging the knurled head 74 is a resilient member 75, by means of which the knurled head 74 is prevented from rotation. This passageway 72 leads to the interior of the carbiuetor chamber 11 and furnishes the air for the carburetor when the motor to which it is attached is operating at what is commonly know. as idling speed, it being understood that at this speed the sleeve 30 is positioned to shut off the main supply of air to the carburetor chamber 11.

The device operates in the following manner: All of the parts are shown in the drawing as in the position which they occupy when the motor to which the carburetor is attached is at idling speed. lVhen it is desired to advance the speed of the motor, it is only necessary to rotate the sleeve 30 about the body of the carburetor and bring the openings Blof the sleeve 30 into registration With the openings 12 in the carburetor chamber 11. Simultaneously With this operation, through the medium of the pin 47 Which serves to rotate the dome-shaped member 46, the needle valve Will be Withdrawn from its seat to permit a greater flow of fuel through the passage 27, this being accomplished by reason of the dome-shaped member 46 and its threaded engagement With the nut 4,3, said dome-shaped member engaging the nut 57 carried by the stem 50 to unseat the needle valve. Y

lVhen it is desired to run the motor at high speeds on a reduced fuel mixture, it is only necessary to rock the stop about its pivotal point until its end 66 rides up on the portion of the sleeve 30 and then upon rotation of the sleeve 30 in the opposite direction to that above described, as the air ports 12 in the carburetor chamber ll are open, the supply of fuel will be reduced since the needle valve will be advanced to- Ward its seat during this operation. The movement of the sleeve 30 is automatic under the influence of the spring of the throttle or accelerator. It must be borne in mind that the connections between the throttle or accelerator and the operating means of the carburetor must be slightly modified to accommodate them to the arrangement.

When the motor. is standing still and it is desired to start the same, it is only necessary lto rockthe bell crank lever 6l about its pivotal point 60, which action serves to completely unseat the needle valve and permit of the raw fuel entering the fuel passage of the elbow l-/i and subsequently entering the motor.

By this construction it is apparent that when the parts are in the position shown the carburetor is supplied with raw fuel with but little air, that is, only what air enters through the idling port 72.

If it is desired to obtain a liner adjustment than is had by the pitch of the thread 45 on the nut 43, it is only necessary to remove the set screw 44 from the nut 43 and pass the same into an opening 76 in the dome-shaped member 4G. This action locks the domeshaped member to the nut 43 and as the dome-shaped member is rotated the same will be reciprocated a lesser distance owing to the small pitch of the threads of the screwthreaded extension 28 as compared with the thread 45 of the nut 43.

From the foregoing it is apparent that the present invention provides a new and improved form of carburetor in which the proportion of fuel and air may be varied at will. Furthermore, the invention provides a carburetor in which the proportion of air and fuel is automatically changed at the various speeds at which the motor to which the carburetor is attached is operated.

What is claimed is:

l. In a charge forming device, a hollow body forming an air chamber, a rotating sleeve surrounding the body for controlling the admission of air to the chamber, a stop for limiting the movement of said rotating sleeve one direction, and means for rendering said stop inoperative to permit of further. movement of the sleeve inone direction which is opposite to that of the `normal direction of movement, means for supplying fuel to the charge forming device, means connected with the sleeve for causing varying of the flow of fuel in proportion to the volume of air admitted, said sleeve when rotated in the direction indicated beyond the normal position causing a'gradual decrease in the fuel supply while increasing the quantity of airA delivered.

2. In a charge forming device, a hollow body forming an air chamber, a rotating sleeve surrounding the body for controlling the admission of air to the chamber', a stop for limiting the movement of said rotating sleeve in one direction, means for rendering said stop inoperative to permit of further movement of the sleeve in one direction which is opposite to that of the normal direction of movement, means for controlling the supply of fuel to the charge forming device, means for operatively connecting the sleeve with the means for controlling the fuel supply so that when the sleeve is rotated for increasing` the volume of air, the flow of fuel is diminished until a predetermined position of the sleeve is had, said sleeve when rotated beyond the normal p0- sition causing limiting of the admission of air to the chamber while increasing the fuel supply.

JAMEs s. curr. 

